Abstract: There are two basic approaches to integrate the Global Positioning System(GPS) with Inertial Navigation System (INS). One approach utilizes the navigation solution of GPS receiver to aid INS. This paper discusses mainly the another approach which utilizes the pseudo range and pseudo range rate measurements of GPS receiver to integrate GRS with INS. It shows that the integrated system pro'vides excellent performance which cannot be achieved by either GPS of ins alone. The improved accuracy is based on the facts that the system uses both position and velocity integration which can complement each other; the system makes the bias of pseudo range measurement observable; comparing with navigation solution of GPS receiver, the system can restrain the effect of GPS Geometric dilution of precision (GDOP) on navigation accuracy. Numerical simulation results are presented to demonstrate the improved performance of the integrated system under different conditions, such as different values of GPS measurement errors, integrating with general GPS or differential GPS.

Key words: global positioning system (GPS), inertial navigation system (INS), integrated navigation system, Kalman filter